Description
Types
Materials
Plate size
Chamber thickness
Filtrate drainage
Max. operating temperature and pressure


Description:

The set of filtration plates creates the working room of the filter press– the filtration chambers. The type and size of the plates are key for the determination of the type and size of the whole filter press.

The filtration plate is equipped with drainage inside the chamber draining the filtrate along the plates to channels inside the plates and out of the filter press. The drainage of membrane plates is located on the surface of a flexible membrane.

 

Types of plates:

  • Frame – consisting of a separate frame and a filtration plate

  • Chamber – the frame and plate of the frame filter press are combined in one unit


  • Membrane – chamber plate equipped with a flexible membrane. It is often combined with chamber plates into a combined set




Materials:

The material used for the production of filtration plates is usually homogeneous PP. Regarding the membrane filter presses, the most frequently used basic material for the body of the plate is PP, the membrane may be made of PP, EPDM, NBR, or rubber, based on the operating equipment. Conductive plates for explosive atmospheres are made of PVDF. Another material may also be used based on the requirements, for example aluminium, stainless steel etc.

The plate material is always selected according to the type of filtered medium and the demands on the filtration process (temperature, pressure). Standard polypropylene is certainly suitable for most processes.

When designing the machine it is necessary to consider other properties of the filtrated medium, such as abrasiveness and settleability. This is then reflected in the structural design of the filtration plate, cloth and the filter press frame.


Plate size

The size is determined by the length of its edge. As a standard, plates with the following dimensions are available:

  •   250 x 250 mm
  •   400 х 400 mm
  •   470 x 470 mm
  •   630 x 630 mm
  •   800 x 800 mm
  • 1000 x 1000 mm
  • 1200 x 1200 mm
  • 1500 x 1500 mm
  • 1500 x 2000 mm


Thickness of the filtration chamber

It is defined as a sum of the depth of the internal recess of two adjacent plates creating a single chamber. In most cases, the depth of the chamber ranges between 10 – 50 mm.


Filtrate drainage

It may be open or closed.

  • Open system

The filtrate is discharged by pipes from each of the plate separately, it flows to the collection trough and it is then drained by pipes.

 

  • Closed system

Collection pipes are drilled through the whole set of plates. These pipes drain the filtrate to the inlet plate and then to the connecting pipes.

  

Max. operating temperature and pressure:

The temperature and pressure of the filtered suspension have a major effect on the plate design. For PP material we offer two basic types of plates: for a maximum pressure of 8 bar, or 16 bar. In both cases, the recommended range of operating temperature of +5 - +40°C is recommended for such pressure. Polypropylene plates can be used at temperatures up to 90°C provided that the filtration pressure is reduced. Filtration in another working area must always be assessed according to the type of filtered medium. If polypropylene is inadequate, it is possible to select another material for the filtration plates.